Thoughts on Coding Style

By Dag, on December 29th, 2016

Based on the Linux Kernel Coding Style document by Linux Torvalds.

This document targets mainly linux kernel programmers, but after many years of programming I personally think these are good basic guidelines and holds good rational for keeping maintainable code in general when programming several languages with various environments, and not just C.

Indentation

Good readability, prevents unnecessary deep nesting. Terminal and cross-editing friendly.
» Tabs at 8 spaces, thus indentations also at 8 spaces.
» Try to avoid more than 3 levels of indentation and stay within column/line-length 80.

Braces

Good readability. Keeps readability without wasting space.
» Opening brace on first line for control structures, next line if long statement(s) forcing multiple lines.
» Opening brace on next line for functions, wherever possible (compiler/parser interpretation).
» Closing brace on single end line, except when followed by a statement continuation (i.e. else if/do while).

Naming

Good readability. Keep it short, descriptive, and simple.
» Global variables and functions must have descriptive names. i.e. count_active_users() NOT cntusr().
» Local variables and functions should have short and to the point names. i.e. tmp vs ThisVariableIsATemporaryCounter, i vs loop_counter.

Functions

Good readability while keeping functions effective.
» Try not to exceed 5-10 local variables.
» Functions should be short and do one thing, and do that well.
» Use helper functions with descriptive names when writing long or complex functions.

Commenting

Write code so it's easy to read, instead of commenting how it works.
» Comment about WHAT your code does, not HOW it does it.
» Functions should only need small comments to note or warn about something, or else it's too complex.
» Put functions on top of blocks, to tell WHAT it does and possible WHY it does it.